The present invention is related to a rotor shaft for a wind energy plant, as well as to a wind energy plant. Wind energy plants with an electric blade angle control (pitch control) are often equipped with a slip ring system, which transmits electric energy and signals as a transmission device from the stationary electric system of the nacelle of the plant into the pitch system in the rotor hub assembly group that rotates with the rotor of the plant. For this purpose, known rotor shafts have a core bore, in which a stationary line pipe (also pitch pipe) extends. The line pipe has the objective to accommodate and protect the electric lines which are to be guided from the stationary nacelle into the rotating rotor hub. Usually, it begins behind the gearbox, where it is also mounted, and guides the lines from there up to the interior of the rotor hub. The line pipe is often mounted on the rotor shaft flange for the fastening of the rotor shaft on the rotor hub by way of a second bearing provided there. In this way, the rotor shaft rotates around the line pipe.
In the known rotor shafts, the line pipe ends in the interior of the rotor hub in a coupling, on which the transmission device is fastened, a slip ring body for instance. The lines guided through the line pipe end in a plug of the coupling, which in turn is connected to a socket of the transmission device. In this, the coupling takes up the inertial forces of the transmission device and guides them into the line pipe. Thus, the transmission device hangs freely in the inner space of the rotor hub. In the case of a slip ring system, the transmission device consists of a stationary inner part (inner ring) and a rotating outer part (outer ring), for instance. Electric energy and control signals are transmitted by way of sliding contacts between the stationary inner ring and the rotating outer ring. Via additional electric lines, which are fastened on the rotating outer ring, the electric energy and control signals are guided into the rotor hub, and there they can feed the pitch control device of the plant, for instance. Inner and outer ring are mounted by way of bearing arrangements. By way of a torque bracket, connected to the rotor shaft at the one side and to the outer ring at the other side, it is brought about that the outer ring rotates along with the rotor shaft.
In known wind energy plants, the transmission device is situated in the interior of the rotor hub, and through this it occupies significant space in the anyway limited inner space of the hub. This makes the work of operators in the inner hub space difficult. In particular, upon entrance into the rotor hub via additional rear entrance openings, an entering person inevitably steps on the transmission device. The same must be protected in a correspondingly sumptuous way. It must be expected that this problem will be aggravated in the future, because future wind energy plants will require greater blade pitch adjustment powers and an increased expense for sensor technology, so that even the dimensions of the transmission devices will increase.
It comes along that with known rotor shafts and wind energy plants, the transmission device can be installed only at the location of the wind energy plant, because otherwise it would be damaged in the transportation of the plant or of the drive train, respectively, or in the building of the plant. This leads to an increased expense for the installation. Besides, the transmission device must be brought into the rotor hub for the installation on location, which means a risk of damage. In addition, the utilisation of known constructions is difficult at rotor shafts formed hollow in a predominant part. Furthermore, the known constructions are sumptuous with respect to their installation and do not always offer sufficient protection for the individual components of the transmission device.
Starting from the discussed state of the art, the present invention is based on the objective to provide a rotor shaft and as well a wind energy plant of the kind mentioned in the beginning, which permits simple installation, simplifies the work in the inner space of the rotor hub and is also flexibly usable.